A genome-wide association study on chronic HBV infection and its clinical progression in male Han-Taiwanese

It is common to observe the clustering of chronic hepatitis B surface antigen (HBsAg) carriers in families. Intra-familial transmission of hepatitis B virus (HBV) could be the reason for the familial clustering of HBsAg carriers. Additionally, genetic and gender factors have been reported to be involved. We conducted a three-stage genome-wide association study to identify genetic factors associated with chronic HBV susceptibility. A total of 1,065 male controls and 1,623 male HBsAg carriers were included. The whole-genome genotyping was done on Illumina HumanHap550 beadchips in 304 healthy controls and HumanHap610 beadchips in 321 cases. We found that rs9277535 (HLA-DPB1, P = 4.87×10^-14), rs9276370 (HLA-DQA2, P = 1.9×10 ^-12), rs7756516 and rs7453920 (HLA-DQB2, P = 1.48×10 ^-11 and P = 6.66×10^-15 respectively) were significantly associated with persistent HBV infection. A novel SNP rs9366816 near HLA-DPA3 also showed significant association (P = 2.58×10 ^-10). The "T-T-G-G-T" haplotype of the five SNPs further signified their association with the disease (P = 1.48×10^-12; OR = 1.49). The "T-T" haplotype composed of rs7756516 and rs9276370 was more prevalent in severe disease subgroups and associated with non-sustained therapeutic response (P = 0.0262). The "G-C" haplotype was associated with sustained therapeutic response (P = 0.0132; OR = 2.49). We confirmed that HLA-DPB1, HLA-DQA2 and HLA-DQB2 loci were associated with persistent HBV infection in male Taiwan Han-Chinese. In addition, the HLA-DQA2 and -DQB2 complex was associated with clinical progression and therapeutic response.